Hi Tomas, > as a proof of concept, I have implemented your zapper demo using svg and > without any javascript, see http://logand.com:2234/
Very nice indeed! SVG is a good alternative to Canvas, it seems. > 1) It uses svg instead of canvas, meaning that: > > - There is no javascript required for drawing stuff. The same > approach to generating html can be used to generate svg. > > - It's easy to define parts of the picture to be clickable, so if you > click on a point in the graph, the text clicked will be updated with > the y axis value, as an example. Also it displays a buuble if you > leave cursor above a point. > > - svg used to be slow, broken and non-portable across browsers a few > years ago but these days, it's rather good for many use-cases. > There are still some things broken on some browsers, but it's > getting steadily better. > > - Graphics transformation can be easily specified in svg, so there is > no need to do "complicated" coordinate calculations. e.g. > > <g transform="translate(0 300) scale(1 -1) translate(0.5 150.5)"> > > changes the orientation and origin of the coordinate system, and > also moves the centres of lines a bit so that 1px lines are sharp > (which is what you discussed with Jon I guess, and which your > example doesn't do for the horizontal axis I think). > > 2) The example doesn't use any javascript meaning that the maximum > refresh speed is 1s. This is good enough for many use-cases. If > not, a bit of javascript can be added in a similar way like the > current picolisp refresh is implemented. As you mentioned, something > like the +Auto class. > > If the automatic refresh is not desirable for the whole page, the > whole svg graph could be put into an iframe which would refresh, but > the surounding html would stay. But it's not critical for this demo. This makes a lot of sense. Thanks! ♪♫ Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
